Volcanic Ash: RAO (recurrent airway obstruction)

[Guest guest]

Volcanic Ash and Equine Respiratory Health

by: Christa Lesté-Lasserre April 16 2010, Article # 16196

Ash and gases emitted since Wednesday's initial eruption of the Eyjafjallajokull

volcano in Iceland could pose breathing risks to anyone exposed, including

horses, according to a European equine researcher whose work centers around

respiratory disease.

Local horses (living near the volcano) could experience unconsciousness,

asphyxiation, or death due to toxicity from carbon dioxide and hydrogen sulfide,

said , DVM, MSc, PhD, researcher at the Duncombe Laboratory in

France. Hydrogen sulfide and ash could also provoke bronchial constriction,

cough, and bronchitis among horses within the country and beyond, he added.

Endometritis in mares

Bronchoalveolar Lavage (BAL) procedures can be used to help diagnose respiratory

diseases in horses, including illnesses resulting from exposure to volcanic ash

and gases.

Throughout Europe, respiratory problems in horses will follow a similar

geographical path as for humans. " Indeed, RAO (recurrent airway

obstruction)-affected horses will predominantly represent the 'at risk'

population, like asthma in humans, " said.

Veterinarians and researchers are having to rely mainly on human data to predict

the effects on horses because so little information currently exists for

equines. Even less information is available on long-term effects, and the

results of research on long-term effects of gas exposure in humans are

controversial, said. Ash could possibly trigger more cases of equine

RAO—as it appears to cause silicosis and chronic obstructive pulmonary disease

(COPD) in humans—but there is currently no published data to support this, he

said.

The best way to protect horses from post-volcanic eruption sicknesses is to get

them away from the affected air, said. " The scale and nature of

respiratory effects deeply depend on the concentration, size, and mineralogical

composition of the ash particles inhaled, " he said.

Horses in close proximity to the volcano should be evacuated, and those in

peripheral areas should be kept indoors as much as possible. Owners should

follow weather reports to know if ash clouds are coming their way. Healthy

horses should not be exercised strenuously outside (on a racetrack, for

example), and those with pre-existing respiratory diseases should not be

exercised at all.

If a horse does show severe breathing difficulties, it should receive prompt

veterinary attention, said. Acute cases will require critical care with

oxygen therapy and bronchodilators, whereas less severe reactions can probably

be controlled with medications.

http://www.thehorse.com/ViewArticle.aspx?ID=16196